POOR relationships between parents and their children are the major cause of young people running away from home, a report said today.

The Children's Society study showed that communication problems in families often reach crisis point at times of major change, such as separation or divorce.

Children in stepfamilies are three times more likely to run away or be thrown out of the family home than those living with their two parents.

Children in single parent families are twice as likely to run away or be forced to leave.

"This research shows that the most significant factor in running away is the quality of relationships between children and parents," said Ian Sparks, chief executive of the Children's Society.

"Family relations are under most stress in periods of family change and upheaval. The `emotional triangle' when children feel they are competing for attention in a new family often leaves them feeling particularly vulnerable. For some children running away can seem the only option."

The Children's Society called for more family mediation to help reduce tension between parents and children.

The study, entitled Home Run: Families and Young Runaways, was based on a survey of 13,000 teenagers aged 14 to 16 in 134 schools across the UK.

Researchers also carried out interviews with 200 young runaways.

An estimated 100,000 under-16s run away from home or from care every year - 14,000 of them are forced to leave by parents or carers, the charity said.

About one in seven of those who run away end up suffering violence or sexual abuse, especially those who sleep rough.

Around one in nine youngsters in the UK will run away for at least one night before the age of 16.